Compound of acetyl cellulose and process of making such compound.



in s'rnrns ATENT OFFICE.

WILLIAM G. LINDSAY, 0F CALDWELL, NEW JERSEY, ASSIGNOB TO THE CELLU'LOID COMPANY, OF NEW YORK, N. Y., A CORPORATIQN OF NEW JERSEY.

COMPOUND OF ACE'IYL CELLULOSE AND IPBOCESS OF MAKING SUCH QOMPOUND.

No Drawing.

Specification of Letters Patent.

Patented Oct. 15,1912,

Application filed November 27, 1911. Serial No. 662,741.

To all whom it may concern:

a citizen of the United States, residing in Caldwell, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Cellulose and Processes of Making Such Compounds, of which the following is a specification. p

The various compositions to which the present invention relates are employed in the arts, generally as imitations of natural substances, sometimes in their original finished form with or without incorporated. colors and other inert substances, and sometiines as films which are'used' for photographic and other purposes. 7

Although the final or useful form-of the difierent compounds of acetyl cellulose'isthat of a solid material, the different processes ofconversion into this final solid form involve, as is well understood, the employment of solutions or mixtures of varying consistency as to plasticity, stiffness, or fluidity, depending generally upon the proportion and kind of solvent .used to the amount of the original base-acetyl cellulose. r r

It has long been known that camphor' mixed with nitrocellulose becomes a solvent of the nitrocellulose in the cold when ethyl alcohol is added to a mixture of these two substances. I have found, however, that when that process is applied to acetyl c'ellulose, no solvent action takes place in the cold or at the ordinary temperature of the room, and the object of my invention was to find substances which, when added to the acetyl cellulose, would exert a solvent action upon the cellulose and produce a plastic mass which could be worked in a manner analogous to nitrocellulose-camphor compounds, and in addition thereto decrease the inflammability of the resulting composition.

In the course of my experiments I have found that a mixture of camphor and methyl alcohol and triphenyl-phosphate, and a mixture of camphor and methyl alcohol and tri-, cresylphosphate or a similar substance, in proper admixture will not only dissolve acetyl cellulose of the variety which is soluble in acetone in the cold, or at room temperature, when used in certain proportions, but will render the product practically noninfiammable. The proportions are important in the practice of the invention.

Compounds of Acetyl As one example of carrying out my invention, I take 100 parts of an acetyl celluor otherwise mix it with from, say, 15 to 30 parts of camphor and about 10 to 20 parts of either triphenylphosphate or tricresylphosphate, so that there is a thorou h mixture of the ingredients. I then add rom about 40 to 50 parts of methyl alcohol and stir until a substantially uniform mixture is produced. I then allow the mass to soak or macerate at room temperature in a closed vessel for from, say, 18 hours to a longer time, until gelatinization has taken place. The mass can then be worked in a heated press, or

upon rolls, or in a stufi'er, as is customary in making nitrocellulose compounds.

The essence of my invention lies in the discovery that while a mixture of ethyl alcohol and .camphor is not a solvent of acetyl cellulose in the cold as it is of nitrocellulose, and that while methyl alcohol b itself is not a solvent of acetyl it is of nitrocellulose, yet a mixture of camphor and meth 1 alcohol in certain proportions will disso ve acetyl cellulose of the variety named at the ordinary. or room, temperature, and thatthe addition of triphenylphosphate or tricresylphosphate or a similar substance, 1n about the proportions named,.is possible, and will decrease the inflammability of the resultant product. I Of course, if. desired, the methyl alcohol can be incorporated with the acetyl cellulose first, and the phosphates named and the camphor can be added subsequently to complete the solvent mixture, whereupon gelatinization takes place; or the'acetyl cellulose, methyl alcohol and the phosphates. may be mixed together first and the camphor subsequently added; but I prefer to mix the solids together first and subsequently add the liqui s. If it is of the solids in order to produce a material having a high degree of hardness or solidity, and if this decrease in the amount of soli 5 used results in the employment of a mixbrought about by heating a mixture containing as low as even 10 parts of the other solids to 100 parts of acetyl cellulose and 50 or more parts of methyl alcohol. In other words, I have found thatthe conversion of lose which is soluble in acetone and grind it desired to use a small proportion ture having apparently little or no solvent action in the cold, gelatinizaton may be my new compound takes place in the cold or at room temperature, but that the conversion is not deterred or hindered, but is on the other hand, rather aided by the applige tion of heat up to 100 C.-

Having thus described my invention, what I.c1aim is:- Y

- 1,.1 The; process of dissolving or converting an acetyl cellulose that is soluble in acetone .Which consists in dissolving or converting said acetyl cellulose by the'use of camphor 'andmethyl alcohol in the presence of one-or 4 more of the group of phosphates described (triphenyl phosphate, tricresyl phosphate),

substantially as set forth.

2. The process of dissolving or converting an acetyl cellulose that is soluble in acetone which consists in (1) mixing saidacetyl cellulose with camphor and one ormore of the I group of phosphates described (tripheiiyl phosphate, tricresylphosphate) and (2) addifng methyl alcohol, substantially as set orth.

,3. The process of dissolving or converting an acetyl cellulose that is soluble in acetone which consists in dissolving or converting said acetyl cellulose by the use of camphor and methyl alcohol in the presence of one or more of the group of phosphates described J. E. HINnoN HYDE, ,MABEL DENTON. 

